Celtic demolished Kilmarnock 5-1 at their Rugby Park home to reach the Scottish Cup quarter-finals.

Scott McDonald scored twice for Gordon Strachan's side while Gary Caldwell, Jan Vennegoor of Hesselink and new signing Georgios Samaras added further strikes.

Jamie Hamill added a consolation for Kilmarnock.

Celtic began to threaten, mainly through McDonald, after a solid Killie start. The Australia striker opened the scoring after 22 minutes to earn the half-time lead, finishing a Paul Caddis cross from close in.

Caldwell made it two with his head seven minutes into the second half and the match was taken beyond the home team when Vennegoor of Hesselink, who also saw a header hit the inside of the post, added a third minutes later.

Hamill pulled one back - nodding home Danny Invincibile's ball in - to give Kilmarnock a glimmer of hope halfway through the half, only to see McDonald strike again to re-extend the lead a minute later.

Samaras, a transfer window signing from Manchester City, came on immediately after that goal and made an impact.

Cutting in from the left, he curled the ball low inside the far post to seal the thrashing with five minutes left on the clock.

Hamilton were knocked out of the Scottish Cup for the second time this week - but only after giving Aberdeen a fifth-round fright at Pittodrie.

The First Division leaders approached their second chance in the cup with relish after Brechin's expulsion, and they created numerous chances.

But Zander Diamond slotted home against the run of play in the 64th minute to continue Aberdeen's challenge on all fronts.

St Mirren blew a string of chances to book a Scottish Cup quarter-final berth and now face a Tannadice replay against Dundee United following a 0-0 draw.

Polish goalkeeper Lukasz Zaluska kept the home side at bay in the first half with poor finishing thwarting their second-half display.

United were hugely disappointing and will have been glad to take the tie back to Tayside when they should have been reflecting on their exit from the competition.

The only other goals on Saturday came from Queen of the South , who went through with a 2-0 win at Morton.

Sean O'Connor put the visitors in front a minute after half-time and John Stewart sealed the victory three minutes of time.

Elsewhere, the Livingston v Partick clash ended goalless

Jonathan Symcox & / Reuters